Epidemiology

Death rate from malignant cancer per 100,000 inhabitants in 2004.^[99]

  no data

  ≤ 55

  55-80

  80-105

  105-130

  130-155

  155-180

  180-205

  205-230

  230-255

  255-280

  280-305

  ≥ 305

In 2008 approximately 12.7 million cancers were diagnosed (excluding non-melanoma skin cancers and other non-invasive cancers) and 7.6 million people died of cancer worldwide.^[3] Cancers as a group account for approximately 13% of all deaths each year with the most common being: lung cancer (1.3 million deaths), stomach cancer (803,000 deaths), colorectal cancer (639,000 deaths), liver cancer (610,000 deaths), and breast cancer (519,000 deaths).^[100] This makes invasive cancer the leading cause of death in the developed world and the second leading cause of death in the developing world.^[3] Over half of cases occur in the developing world.^[3]

Global cancer rates have been increasing primarily due to an aging population and lifestyle changes in the developing world.^[3] The most significant risk factor for developing cancer is old age.^[101] Although it is possible for cancer to strike at any age, most people who are diagnosed with invasive cancer are over the age of 65.^[101] According to cancer researcher Robert A. Weinberg, "If we lived long enough, sooner or later we all would get cancer."^[102] Some of the association between aging and cancer is attributed to immunosenescence,^[103]errors accumulated in DNA over a lifetime, and age-related changes in the endocrine system.^[104]

Some slow-growing cancers are particularly common. Autopsy studies in Europe and Asia have shown that up to 36% of people have undiagnosed and apparently harmless thyroid cancer at the time of their deaths, and that 80% of men develop prostate cancer by age 80.^[105][106] As these cancers, often very small, did not cause the person's death, identifying them would have represented overdiagnosis rather than useful medical care.

The three most common childhood cancers are leukemia (34%), brain tumors (23%), and lymphomas (12%).^[107] Rates of childhood cancer have increased between 0.6% per year between 1975 to 2002 in the United States^[108] and by 1.1% per year between 1978 and 1997 in Europe.^[107]

Epidemiology

Although reported incidence rates have increased in the past 20 years, mesothelioma is still a relatively rare cancer. The incidence rate varies from one country to another, from a low rate of less than 1 per 1,000,000 in Tunisia and Morocco, to the highest rate in Britain, Australia and Belgium: 30 per 1,000,000 per year.^[38] For comparison, populations with high levels of smoking can have a lung cancer incidence of over 1,000 per 1,000,000. Incidence of malignant mesothelioma currently ranges from about 7 to 40 per 1,000,000 in industrialized Western nations, depending on the amount of asbestos exposure of the populations during the past several decades.^[39] It has been estimated that incidence may have peaked at 15 per 1,000,000 in the United States in 2004. Incidence is expected to continue increasing in other parts of the world. Mesothelioma occurs more often in men than in women and risk increases with age, but this disease can appear in either men or women at any age. Approximately one fifth to one third of all mesotheliomas are peritoneal.

Between 1940 and 1979, approximately 27.5 million people were occupationally exposed to asbestos in the United States.^[40] Between 1973 and 1984, the incidence of pleural mesothelioma among Caucasian males increased 300%. From 1980 to the late 1990s, the death rate from mesothelioma in the USA increased from 2,000 per year to 3,000, with men four times more likely to acquire it than women. These rates may not be accurate, since it is possible that many cases of mesothelioma are misdiagnosed as adenocarcinoma of the lung, which is difficult to differentiate from mesothelioma.